Skiving-machine



2 Sheets-Sheet E. GOTT.

SKIVING MACHINE.

(Nb Model.)

Patented Jan. 3, 1888.

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(Nb Model.)

4 Q 2Sheets-Sheet 2. E. GOTT.

SKIVING MACHINE.

No. 875,811. Patented Jan. 3, 1888.

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UNITED STATES PATENT OFFICE.

ERASTUS eorr, on nnw'ron, MASSACHUSETTS.

SKIVING-MACHINE.

m I SPECIFICATION forming part of Letters Patent No. 375,811, dated January 3, 1888.

Application filed June 17, 1887. Serial No. 241,628.

To all whom it may concern.-

Be it known that I, ERAsTUs GOTT, a citizen of the United States, residing at Newton,in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Skiving-Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

This invention relates to machines for skiving leather or other similar material, the essential features of which consist, first, in disposing the cutting-knife upon along swinging arm, whereby a change in the position of the knifevertically, either in raising or lowering it to accommodate leather of varying thickness, will produce a minimum movement lat erally in either direction of the knife with respect to the periphery of the lower feed roll or bed. Furthermore, in securing the knife to a stock placed in the end of the swinging arm, said stock being capable of partial rotation, to allow alteration in the angle of the knife in skiving, the axis of such rotation being in alignment with the inner vertical face of the lower feed roll or bed; hence change of angle in the knife does notalter its lowest cuting-point with respect to the circular beda very important feature; secondly,in having the cutting-edge of the knife so adj usted upon the lower feed roll or bed as to meet a vertical plane drawn through the center of said bed at right angles to its rotation; thirdly, in so disposing the spring presser-foot and the top feed-rolls with reference to the guide-plate that the said feed-rolls shall extend through said pressenfoot and engage and press the material upon the bed and thereby induce proper feed motion; fourthly, in the general arrangement and disposition of parts, to be hereinafter more fully described.

The drawings accompanying this specification represent, in Figure 1, a front elevation, and Fig. 2, a plan of a leather-skiving machine embodying my invention. Fig. 3 is an end elevation with the support P sectioned and the front portion removed. Fig. 4 is a (No model.)

plan of the presser-foot with the upper feedrolls removed. Fig. 5 is a crosssection through the rotary knife-block on line x at of Fig. 2. Fig. 6 will illustrate a modification of Fig. 5.

In the drawings, A represents a standard, of which B is the base, and G a vertical rib formed thereon. The latter is bored its e11- tire length to receive the shaft D, which is mounted in suitable bearings and furnished at one end with the corrugated lower feedroll or cylindrical bed, E, with which the cutter co-operates when skiving material. The other and opposite end is provided witha spur-gear, F, which meshes with a similar but smaller gear, G, fitted upon the shaft H.

Upon the rib O, at a point near the gears F G, I have formed a boss or support, 0, for the arm or head I, which extends parallel with but above the rib O. This head is securely bolted to flanges cast on O, and becomes an integral portion thereof. The head I is also bored longitudinally and provided with a shaft, H, to which, as before mentioned, is affiXed the gear G, the two shafts D H being parallel and in vertical alignment one with the other. Moreover, the rear extremity of the shaft H is provided with a driving-pulley, J, by which motion is transmitted to the entire operative mechanism of the machine.

In the front end of the head I, I have formed a slot, a, to containa movable spring-adjusted box, I), in which the front end of the shaft H revolves. Movement of the screw 0 raises or depresses this shaft H, and with it the upper feed-rolls, d d, which are roughened or furnished with blunt teeth and mounted thereon. This adjusting mechanism is to adapt the rolls to feed material of various thicknesses.

' To the under side and upon the end portions of'the head I, I have bolted a flat spring or presser-foot, e, which extends over the top of thecircular bed E, but to one side of it, andwith the front edge, or that adjacent to the 5 cutting-edge of the knife, coincident with a plane drawn vertically through the center of the bed,E. The cutting-edge ofthe knife is ad justed close up to this edge to prevent the material from lifting while being operated on, as the spring 0 retains it closely to the bed E and acts as a presser'foot .to maintain the leather upon the bed E., I have, moreover, formed an opening, f, to admit not onlythe feed-roll d below upon the bed E, but also to permit the guide-plate g to project upward above the-top periphery of the bed E and the feed-roll d.

.The spring 6 is further provided with a second opening or slot, f adapted to admit of a second feed-roll, d, upon the extreme outer end of the shaft H, in order to facilitate the feed. I have found in practice that the extreme outer end of the presser-foot or spring 0 has a tendency to rise, and after continued use to lose its power, when the material will fail to be properly fed, one edge (the inner) advancing more rapidly than'the outer. To obviate this difficulty I have constructed a support, 1?, in alignment with the head I, and forming a continuation thereof. This support extends above the presser-foot, and is provided with a downwardly-projecting arm, Q. centrally bored at B. This bore receives and contains a springactuated stud, S, which bears and rests upon the extremity of said presser-foot e, the amount of pressure upon the latter being adjusted by means of the screw T. By this arrangement the presser-foot bears equally at all times upon the upper surface ofthe rotary bed E', andthe travel of the material across its face in the process of skiving is the same at all points.

The guide-plate g is shown as bolted to the top of G, and is adjusted closely to the rear vertical face of the bed E and provided with a horizontal step, it. This latter is flush with the top point or extreme upper portion of the periphery of the bed E. The upper feed-roll d laps the point between the bed E and plate {1, and the material fed to the machine has no tendency to crowd and jam between the bed and guide-plate, as it is supported by the step h, before mentioned.

Upon the rear of the head I, I have disposed and pivoted at i a swinging arm, K, cast with an offset, upon which is disposed a cylindrical arm or bracket, L, holding the adjustable head-stock and its cutting-knife M. To permit raising of the knife relatively to the periphery of the bed E,in order to operate upon thick or thin material, I have formed abracket, j, into which the arm Kslides,while themovement of the latter is effected by the adjusting thumb-screw 7c, located upon the bracket. A second screw, Z, to be used as a cheek, is disposed in the bracket and locks the arm in position after proper adjustment.

To effect alteration in the angle of the knife M relatively to the periphery of the bed E, in order to change the slope of the angle given to the material in skiving, I have perforated the arm L longitudinally with a bore, m, at right angles to the shafts D H, and, further, pierced it with a radial slot, n, which extends its entire length and opens into the bore m. Within the latter is fitted a short cylindrical stock, N, slotted at 0 its entire length, the width of this slot being just equal to the thickness of the knife M, which latteris secured to its stock N by the screw 19. It will be observed that theknife projects beyond the axis of the knife-stock, in which it is secured; but

since it becomes necessary to change the angle of the knife, the radial slot a, before mentioned, is formed,which enables free rotation of theknife and its stock in the arm L,to there by provide for any suitable angle for skiving. When properly adjusted to the desired angle, the thumb-screw q secures the whole rigidly in place. i

The arm L is pierced its entire length. Thus, in case the knife requires to be taken out and sharpened, the screw 19 is relaxed and the knife slipped out at the rear. 'Iheknife-stock N is not altered or moved, but remains rigid, and the knife can be reinserted and work recommenced without any further adjustment. To prevent end-play of the knife-stock N, two pins, 8 t, are inserted,which bear against each end of the support L. The rear one I have made of considerable length, to be used as a lever, by which to readily turn the stock N in its bearings after raising the check-screw q when adjustment in the angle of the knife is required. The center of rotation of theknife stock N and its knife M is in alignment vertically with the edge r of the guide-plate 9, (see Fig. 2;) hence any change in the angular position of the knife does not alter its position laterally of the guide-plate, and no furtheradjustment is required-a very important feature in machines of this class.

The center of rotation of the knife is the center of the stock N; but as the knife extends both sides of the center the axis of rotation of the knife is in the plane y 1 Fig. 5, and this plane is coincident with the front edge of the step It, as shown at r. This construction always maintains a portion of the cutting-edge of the knife beyond the vertical inner edge of the guide-plate (see Fig. 2) and insures proper skiving of the material, which does not always occur when one corner of the knife is in alignment with the guide-plate.

In Fig. 6 Ihave shown a slight modification in the construction of the arm L, in which the radial slot n is extended through the material composing said arm and is open its entire length. 7 This serves to admit or withdraw the knife through it, and also permits the use of a wider knife; hence release of the latter is easily effected by turning the holding-screw p, when the knife can readily be taken out.

I claim- 1. In leather-skiving machines, the combination, with the rotary circular bed, spring presser-foot, feed-rolls, and guide-plate, of the IIO cutter or knife disposed upon a swinging adcarried thereby, incombination with a rotary bed, and the swinging arm L, by means of which vertical adjustment of the knife may be effected and the cutting-edge thereof is maintained in the same vertical plane axially of the rotary bed E. u

4. The combination, with the rotary bed E and its operative parts, of the swinging arm K, the arm L, with its bore m and radial slot n, and the knife-stock N, carrying the knife capable of semi-rotation, with its axis of r0- tation in alignment with the inner vertical face of the rotary bed E, substantially as stated.

5. The combination, with the standard A, head I, rotary bed E, presser-foot e, and feedrolls d d of the swinging adjustable arm K, carrying the adjustable knife M, by which the latter can be raised or lowered vertically with respect to the periphery of said bed E, substantially as set forth.

tially as herein described.

7. A springactuated presser-foot, e, as herein described, and provided with the slots ff combined with the feedrolls d d rotating within such slots and adapted to co-operate with the rotary bed E to feed the material against an adjustable knife, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

ERASTUS GOTT.

WVitnesses:

H. E. LODGE, F. CURTIS. 

